Governors for internal combustion engine liquid fuel injection pumps



June 23, 1959 J. W. CLEGG GOVERNORS FOR INTERNAL COMBUSTION .ENGINE LIQUID FUEL INJECTION PUMPS 3 Sheets-Sheet 1 Fil ed Jan. '21. 1958 Fig.1

L LU 812F601" June 23, 1959 w CLEGG 2,891,533

J. GOVERNORS FOR INTERNAL COMBUSTION ENGINE LIQUID FUEL INJECTION PUMPS Filed Jan. 21,1958 3 Sheets-Sheet 2 Juhe 23, 1959 w c GG 2,891,533

J. LE GOVERNORS FOR INTERNAL COMBUSTION ENGINE LIQUID FUEL INJECTION PUMPS Filed Jan. 21, 1958 3 Sheets-Sheet 3 United States Patent GOVERNORS FOR INTERNAL COMBUSTIQN ENGINE LIQUID FUEL INJECTION PUMPS John William Clegg, Kenton, England, assignor to C.A.V. Limited, London, England Application January 21, 1958, Serial No. 710,323

Claims priority, application Great Britain January 21, 1957 1 Claim. (Cl. 123140) A known form of control means for an internal combustion engine liquid fuel injection pump, includes a longitudinally slidable rod which is responsive to the action of a governor for varying the pump output under varying conditions of load and speed, the governor being a pneumatic device of the kind consisting in part of a spring loaded diaphragm (or piston) connected to the said rod and movable by pressure of the air in the airintake manifold of the engine.

When the engine is running at low speed and under a low load, the action of the governor is apt to be unstable, in that the diaphragm (or piston) is liable to flutter, and so cause the engine speed to fluctuate erratically.

Various forms of stabilising means are already known for minimising the above mentioned condition, and the object of the present invention is to provide a stabiliser in an improved form whereby the desired result can be obtained in a very simple and reliable manner.

A governor of the kind aforesaid in accordance with the invention includes a stabilising air buffer connected to the diaphragm (or piston) through a spring, and a valve whereby the buffer can be rendered ineffective.

In the accompanying drawings, Figures 1, 2 and 3 are similar sectional side views illustrating respectively three embodiments of the invention.

In one example of a governor in accordance with the invention, and as illustrated by Figure 1 of the accompanying drawings, there is provided an axially located buffer cylinder a within the body part b of the governor at the end remote from the diaphragm c, and in the cylinder is contained a piston d which is connected to the diaphragm by a spring e, the diaphragm being loaded by another springf in the usual manner. The diaphragm has attached to it the slidable rod g which regulates the pump output. If desired the diaphragm may be substituted by a piston. The body part b is connected as shown to the air-intake manifold h by a pipe 1'.

In combination with the buffer cylinder is arranged a valve k of the rotary plug type which is connected through the accelerator pedal m to the throttle n in the air-intake manifold. During normal running conditions the valve is open to the atmosphere, the valve being closed only when the engine is running slowly under a light load.

Alternatively and as shown in Figure 2, the valve may consist of a plug 0 slidably contained in a cylinder p which at one end is open to the atmosphere and which at the other end is connected by a pipe q to the inlet end of the air-intake manifold, the valve being closed when the engine is running slowly, and being opened by the reduced pressure in the manifold when the engine is running at high speed.

As an alternative to the arrangement shown in Figure 2, the device shown in Figure 3 may be employed. This consists of a resilient diaphragm r serving as a valve and co-operating with a seating s at one end of the cylinder a. The diaphragm is contained in a compartment t. One side of the compartment is connected to the manifold by a pipe q, and the other side is in communication with the interior of the body part b through an orifice u.

In each of the arrangements above described the action is such that when the buffer valve is closed, the spring connecting the piston 01 to the diaphragm 0 serves to damp out undesired movements of the governor diaphragm (or piston).

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

A pneumatic governor for controlling the output of a liquid fuel injection pump whereby fuel is supplied to an internal combustion engine having an air-intake manifold controlled by a throttle, comprising in combination with a movable member for varying the pump output, an airpressure responsive member arranged to actuate said movable member, a hollow body part forming a chamber which at one end is closed by said air-pressure responsive member, and through the medium of which a one side of said air-pressure responsive member is exposible to the air pressure in a part of the air-intake manifold, a buffer air cylinder situated at the opposite end of said chamber, and having one end open to the interior of said chamber, a piston slidable in said cylinder, a spring interconnecting said piston and movable member, and a valve arranged to control the flow of buffer air into and out of the end of said cylinder remote from that open to the interior of said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 2,633,115 Waring Mar. 31, 1953 2,698,614 Nicolls Ian. 4, 1955 2,752,906 Nicolls July 3, 1956 FOREIGN PATENTS 645,993 Great Britain Nov. 15, 1950 

